When Kelvin Gastelum defeated fellow middleweight Uriah Hall at The Ultimate Fighter 17 Finale in April, many wondered if the upset victory was a fluke occurrence or a sign of bigger things to come.

On Wednesday night at UFC Fight Night 27 from the Bankers Life Fieldhouse in Indianapolis, Gastelum made a point to silence any doubters when he submitted Brian Melancon in the first round.

Gastelum, who was making his 170-pound debut, started the action off with clear purpose. The 21-year-old stalked with workmanlike patience and peppered the Houston native with effective jabs and leg kicks, looking to open his opponent’s defense.

Roughly forty seconds into the opening round, Gastelum shot for a double-leg takedown, dragging Melancon to the mat. For most, Gastelum’s wrestling was a focal point heading into this fight, and the general consensus was that the Yuma, Arizona, native would implore a heavy dose of ground control if he was going to dispatch of Melancon.

However, Melancon rose quickly from that early takedown and the action stayed on the feet for the remainder of the fight, as both fighters began to freely engage all across the Octagon.

With three minutes remaining Gastelum landed a thudding one-two hook combination through Melancon’s guard, and the momentum of the fight shifted towards the loose and visibly confident former TUF winner.

That heavy combination was followed by a slick body kick to Melancon’s rib cage, and Gastelum took note of the damage.

At 2:26, the fight was stopped after a brutal combination from “KG” that was followed with a crescendo-inducing left uppercut that sent Melancon to the mat. Gastelum followed his opponent to the mat almost instantaneously and sank in a fight ending rear-naked choke submission.

It marked the newly minted welterweight’s seventh win in as many fights, and signaled the stocky American’s second consecutive win in the world’s premier fighting organization.

“I knew he had heavy hands coming in. I just wanted to get the finish – take advantage of him being rocked. I took his back, secured the lock,” Gastelum said post-fight.

At just 21 years old, Gastelum is a fighter to watch in the welterweight division.